Self-healing material incorporates carbon from the air
A material designed by MIT chemical engineers can react with carbon dioxide from the air, to grow, strengthen, and even repair itself. The polymer, which might someday be used as construction or repair material or for protective coatings, continuously converts the greenhouse gas into a carbon-based material that reinforces itself.
The current version of the new material is a synthetic gel-like substance that performs a chemical process similar to the way plants incorporate carbon dioxide from the air into their growing tissues. The material might, for example, be made into panels of a lightweight matrix that could be shipped to a construction site, where they would harden and solidify just from exposure to air and sunlight, thereby saving on the energy and cost of transportation.The finding is described in a paper in the journal Advanced Materials, by Professor Michael Strano, postdoc Seon-Yeong Kwak, and eight others at MIT and at the University of California at Riverside
“This is a completely new concept in materials science,” says Strano, the Carbon C. Dubbs Professor of Chemical Engineering. “What we call carbon-fixing materials don’t exist yet today” outside of the biological realm, he says, describing materials that can transform carbon dioxide in the ambient air into a solid, stable form, using only the power of sunlight, just as plants do. Developing a synthetic material that not only avoids the use of fossil fuels for its creation, but actually consumes carbon dioxide from the air, has obvious benefits for the environment and climate, the researchers point out. “Imagine a synthetic material that could grow like trees, taking the carbon from the carbon dioxide and incorporating it into the material’s backbone,” Strano says. One key advantage of such materials is they would be self-repairing upon exposure to sunlight or some indoor lighting. If the surface is scratched or cracked, the affected area grows to fill in the gaps and repair the damage, without requiring any external action. While there has been widespread effort to develop self-healing materials that could mimic this ability of biological organisms, these have all required an active outside input to function. Heating, UV light, mechanical stress, or chemical treatment were needed to activate the process. By contrast, these materials need nothing but ambient light, and they incorporate mass from carbon in the atmosphere, which is ubiquitous.
Further information: www.mit.edu